Current commercial transport aircraft typically include deployable high lift devices that change the aircraft wing shape depending on fight conditions. These devices can include leading edge flaps and/or slats, and trailing edge flaps that are extended to increase lift during takeoff and landing. In some cases, it has been contemplated to move these devices using eccentric cams, as disclosed in U.S. Pat. No. 6,802,475, issued Oct. 12, 2004, which is fully incorporated herein by reference. During cruise flight, these devices can be retracted to reduce aircraft drag. Commercial transport aircraft can also include spoilers to selectively reduce lift and/or increase drag during various phases of operation (e.g., descent, landing, and aborted takeoffs). On some aircraft, spoilers can be used to provide roll control of the aircraft.
FIG. 1 is a partially schematic cross-sectional illustration of a wing 92 with a spoiler 94 and a flap 96 in a retracted position configured in accordance with the prior art. FIG. 2 is a partially schematic cross-sectional illustration of the wing 92 shown in FIG. 1 with the flap 96 in an extended position. The flap 96 is coupled to a support 75 via a first flap link 71. A drive mechanism 10 is connected via a torque tube 97 to a flap drive unit 50. The flap 96 is operatively connected to the flap drive unit 50 via the first flap link 71, a second flap link 72, and a lever 73. The flap drive unit 50 is configured to move the lever 73, causing the first flap link 71 to pivot about point B and move the flap 96 between the retracted and extended positions shown in FIGS. 1 and 2 respectively. In the extended position, a gap is created between the trailing edge of the spoiler 94 and the leading edge of the extended flap 96 allowing a first airflow F1 to be energized by the second airflow F2 that flows through the gap.
As the flap 96 moves from the retracted position (shown in FIG. 1) to the extended position (shown in FIG. 2), a first interconnect link 61 causes a second interconnect link 62 to pivot about a fixed point C, moving the spoiler actuator 30 and causing the spoiler 94 to droop (e.g., causing the spoiler 94 to rotate about point A with the trailing edge of the spoiler 94 moving toward the leading edge of the extended flap 96). This spoiler droop can improve airflow (e.g., airflow F1 and airflow F2) proximate to the wing 92, and the extended flap 96 as compared to when the spoiler 94 is not drooped. This improved airflow can improve overall performance of the wing 92 by increasing lift, decreasing drag, and/or improving high angle of attack characteristics.
A problem with this configuration is that the first and second interconnect links 61, 62 can be required to span significant distances, adding weight and complexity to the flap and spoiler systems. Another problem is that at least a portion of the first and/or second interconnect links 61, 62 are required to extend into the cove area 65 where the flap support 75 and the first flap link 71 are located. Accordingly, when the flap 96 is extended, the portions of the first and/or second interconnect links 61, 62 can interfere with the second airflow F2 through the gap between the spoiler 94 in the flap 96 proximate to the cove area 65, reducing the performance benefits provided by the gap. Yet another problem with this configuration is that the spoiler actuator 30 must be positioned proximate to the flap drive unit 50, support 75, and first flap link 71, which can result in the spoiler actuator 30 being positioned at a less than desirable location. For example, in certain situations, the spoiler actuators 30 must be positioned away from the center of the spoilers 94 or multiple spoiler actuators 30 must be attached to the spoilers 94 asymmetrically.